Not really necessary IMO. If your IP address is dynamically assigned, as is the case with most routers, just installing arpon is enough. It configures correctly for this arrangement and works neatly in the background, thwarting some of the most notorious pryware available.All the info necessary for other arrangements can be found with # arpon -h .All in all a simple and effective piece of software. A must if you are on a LAN !!